Manufacture of mainsprings for watches



(No Mou-e1.) A A 3 sheetssheet 1. F. PURDY.

,MANUPAGTURB 0F MAINSPRINGS FOR WATCHES. N0. 557,021. Patented Mar. 24, 1896.

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(No Model.) v i 3 Sheets-Sheet 3.

F. PRDY. MANUPAGTURB 0F MAINSPEINGS FOR WATGHBS. No. 557,021. l I PatentedMar. 24,1896.

ANDREW BARAuAMyHUTU-llmm WASMNGTONJI C UNITED STATES PATENT OFFICE.

FRED PURDY, OF ELGIN, ASSIGNOR T0 THE ELGIN NATIONAL IVATCII COMPANY, OF CHICAGO, ILLINOIS.

MANUFACTURE OF NIAINSPRINGS FOR WATCHES.

SPECIFICATION forming part of Letters Patent No. 557,021, dated March 24, 1896.

Application filed May ll, 1898. Serial-No. 473,869. (No model.)

To all wham t may concern:

Be it known that I, FRED PURDY, of Elgin, in the county of Kane, and in the State of Illinois, have invented certain new and useful Improvements in the Manufacture of Mainsprings for lVatches and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying' drawings, in which- Figure l is a plan view of the mechanism preferably employed. Fig. 2 is a side elevation of the same. Fig. 3 is a perspective view of the upper portion of said mechanism and shows the spring-wire in its passage over the abrading-surface. Figs. 4 and A5 are perspective views of the guides employed for controlling the position of said spring-wire, and Fig. 6 is a top plan view with parts removed and broken away to show a means for moving the abrading-belt laterally.

Letters of like name and kind refer to like parts in each of the gures.

The object of my invention is to enable the edges of mainspring-wire to be rounded and finished at one operation; and my said invention consists in the mechanism employed, substantially as and l'for the purpose hereinafter specified.

In the carrying of my invention into practice I preferably employ for an abrading mechanism a belt A, which has its outer face coated with a suitable abrasive material and is arranged upon and around two pulleys B and C that are adapted to be rotated, so as to give to such belt a continuous motion in one direction. Said belt is also, by any suitable means, given a laterally-reciprocating motion, so as to cause so much of its width as may be desired to be presented to an article passed longitudinally over the same. The means shown in the drawings for this purpose consists of a forked arm d, that engages the edges of the lower portion of the belt A, and which is carried by a horizontally-vibratory bar A. A cam H, as shown in Fig. 6, may be employed to continuously actuate the bar AQ so that the lateral movement of the belt may be simultaneous with its longitudinal movement.

The spring-wire D to be operated upon is by any suitable means passed longitudinally permitting of the free passage of the latter permits of no material circumferential movement of the same.

The guides E and E are arranged with their slots in a vertical line, and midway between the same is a third guide G, which consists of a pin that projects downward through the support F and within its lower end is provided with a longitudinal slot g that is also vertical, while between each of said guides E and E and said guide G is a guide G', which is similar to the latter in construction and has its slot g formed with an inclination from a line perpendicular to the plane of the abrading-surface A, that represents the extreme inclination in one direction of the springwire D, with reference to the same, which is necessary in order that the edge of said wire may be given the desired curved or rounded shape. The oppositely-located guide G has its slot arranged in a line opposite to that of the first-named guide G. f

By the described construction and arrangement of guides the spring-wire enters and leaves the field of abrasive action in a position perpendicular to the face of the abrading device, while between the points of entry and exit it is turned to one extreme of inclination and then to the opposite extreme, so that in passing over the abrading-surface each portion of its edge is presented thereto with accuracy and uniformity and upon a curved line that is determined by the extreme opposite inclinations given to'said wire.

If desired, the wire maybe caused to enter and leave the field of action in oppositely-inclined positions, in which event a number of guides would be placed at different points between the end guides, with such relative inclinations of their slots as might be neces- ICO sary to hold the Wire in a regularly-twisted guides, adapted to tWist the spring, a longiform. tudinally-inovable abrading-surfaee that is Having thus described my invention, what adapted to be simultaneously vibrated later- I claim is ally, and means for thus Vibrating the same,

substantially as and for the purpose shown.

In testimony that I claim the foregoing I have hereunto set my hand this 6th day of April, 1893. y

l. As a means of rounding and finishing the edges of mainsprings, the combination of a series of guides adapted to twist the spring, and a fiat abrading-surfaee that is continuons from one guide to another, substantially as and for the purpose speeied.

2. As a means for rounding and finishing niainsprings, the combination of a series oi FRED PURDY.

Witnesses GEO. S. PRINDLE, CARLOS II. SMITH. 

